1. Field of the Invention
This invention relates to railway ties, and more particularly to metallic ties, tie plates and fasteners for use in underground mining.
2. Description of the Prior Art
The use and acceptance of light weight, steel section railroad ties suitable for use in both standard surface gauge and in underground mining is now attractive because the timber tie is now becoming expensive to purchase, transport, rehandle, install, maintain, and in some areas, an unreliable source of supply. The prior art, which is exemplified by such United States Letters Patents as U.S. Pat. Nos. 377,191 (H. D. Cone); 411,958 (R. Forsyth); 446,405 (E. D. DeClements); 802,764 (B. A. Legg); 826,243 (W. C. Gregg); 858,942 (A. M. Baird); 869,645 (M. J. Nolan); 1,071,161 (J. F. Lahart); and 1,214,587 (E. Prendergast), has long been concerned with the development of metallic railroad ties. However, while to some extent such prior art developments have been successful, in general the prior art railraod ties have had numerous short comings. Notable short comings include:
1. High installation time on track sections;
2. The tie cannot be applied to various gauges of railways and weights of rail;
3. There is need for measurement or gauge rods to set the rails in position;
4. Tie sections require substantial excavation at the drift floor;
5. Tie plates utilized with the tie sections do not afford sufficient protection to the tie section if derailment occurs;
6. Specialized tools are required to secure, dismantle or adjust the assembly;
7. The tie sections are unsatisfactory for track which normally requires bonding because they do not provide metal-to-metal contact in track.
8. The tie sections generally cannot be handled by miners with ease and safety.